Table of Contents

July 01, 2017; Volume 174,Issue 4

Cover image

Cover image: The photo shows a clock-wise 90° rotation of a cross-stratified Navajo Sandstone at a location known as ‘The Wave’. The wave outcrops in Coyote Buttes North, part of the Paria Canyon/Vermillion Cliffs wilderness on the borders of Utah and Arizona in USA. The rocks are coloured red by iron oxide which picks out subtle changes in grainsize due to deposition on desert sand dunes that were active in the Jurassic. The large scale sets of cross-strata in the Navajo Sandstone have been sculpted by wind and water to create the flowing shapes of the wave.